Load elevating linkage



July 18, 1961 H. l. BERG LOAD ELEVATING LINKAGE Filed Jan. 1'?, 1958 2 sheets-sheet 1 58 19V aia l,

July 18, 1961 H, BERG 2,992,748

LOAD ELEVATING LINKAGE HAROLD BERG /N VENTO/Q HUEBNER 8 WORREL A VORNE-KS HMM United States Patent 2,992,748 LOAD ELEVATING LINKAGE Harold I. Berg, 121 McKinley, Fresno, Calif. Filed Jan. 17, 1958, Ser. No. 709,574 3 Claims. (Cl. 214-78) The present invention relates to a load elevating linkage tor increasing the mechanical advantage which a driving member has overa driven member and more particularly, to a linkage which enables the application oi maximum lifting force to a load elevating member when the maximum eilective load is borne by the member.

The subject invention is conveniently described in connection with self-loading vehicles of the type shown in the United States patent to Frost No. 2,286,723. Brieiiy, this type of vehicle is 4a dump truck which provides a dump body receptacle for receiving a load of material, such as debris, soil, sand, gravel, or the like; ya pair of arms forwardly extended from and rigidly connected to a shait rotatably mounted in the vehicle transversely thereof for elevational pivotal movement between Ia forwardly extended loading position and an upwardly extended dumping position over the receptacle; a bucket or scoop mounted on the extended ends oi the arms; la lever rigidly radially extended from the shaft; and an hydraulic ram pivotally interconnecting the vehicle and the lever adapted upon expansion and contraction to move the arms between their dumping and loading positions.

This type of loading vehicle is highly advantageous inasmuch as the operations of loading, transporting and dumping aggregate Kand other bulk materials can be accomplished by the driver of the vehicle and without the use of any auxiliary equipment. However, there are -several inadequacies in the known structures or :this type.

Because of the wide Aangular movement of the load supporting arms, it has been necessary to provide a ram having `a relatively long stroke. Further, because of said `angular movement, the extent or vertical pivotal moveinitial lifting force is being applied to the arms by the i ram. As a result, rams having long strokes and great power have been required necessitating heavier, more bulky, and more expensive structure than desired.

.f Accordingly, it is an object oi the present invention to provide a load elevating linkage for increasing the me- `and a telescopically adjustable powered device so that the shaft can be rocked through a predetermined angle while the powered device moves through an appreciably smaller angle.

Another object is to provide a -linkage for interconnecting an hydraulic ram and a rotatable rock shaft rocked by expansion and contraction of the ram which linkage minimizes the stroke and extent of movement of the r-am. i Another `object is to provide an apparatus for eleva- Ationally adjusting a load supporting Iarm mounted on a vehicle ina compact manner and in a minimum of space.

Another object is to enable load supporting arms of Patented July 18, 1961 rice the nature described to be mounted at low positions on'- supporting vehicles.

Other objects are to provide a load elevating linkage' which is simple and economical to construct and operate, dependable in action, durable `form, adapted -to be -in-` stalled on existing vehicles with a minimum of effort, and which is adapted to be used not only on vehicles but in other environments where similar problems are involved.

These, together with other objects, will become more -fully apparent upon reference to the following description and accompanying drawings.

In the drawings:

FIG. l is a side elevation of a self-loading vehicle in which the load elevating linkage of the subject invention is incorporated.

FIG. 2 is a somewhat enlarged, fragmentary, horizontal section taken on line 2-2 of FIG. 1.

FIG. 3 is a somewhat enlarged, transverse vertical section taken online 3 3 of FIG. 1.

FIG. 4 is a still rfurther enlarged, fragmentary, longitudinal vertical section taken on a plane at a position represented by line 4--4 of FIG. 2 and showing the load elevating linkage in a loading position; a load supporting arm is fragment-arily shown in dashed Ilines in loading position.

FIG. 5 is a fragmentary, somewhat enlarged, vertical longitudinal section also taken on a plane at a position represented by line 5-5 of FIG. 2 but showing a load elevating linkage in a load dumping position; a load supporting arm is fragmentarily illustrated in dashed lines in dumping position.

Referring more particularly to the drawings, a dump truck 10, typifying vehicles with which the subject invention is employed, is illustrated in FIG. l and provides'a chassis 11 supported for earth traversing; movement on pai-rs of front and rear wheels 12 and 13. A dump body load receptacle 14 is supported on the chassis for elevational pivotal movement around a substantially horizontal axis member 15 rearwardly of the rear wheels between the loading position, illustrated in FIG. l, and a rearwardly upwardly inclined dumping position, not shown. An angulated shield 16 provides -a portion rigidly connected to the receptacle vand a shielding portion adapted to extend over the cab 17 of the truck when the dump receptacle is in its loading position, as also shown in FIG. l.

The chassis 11 includes a pair of longitudinally extended frame members 25 in transversely spaced relation and conveniently consisting of channel members. A vertical plate 26, best seen in FIGS. 2 and 3, is connected to one of the frame members by bolts 27. A substantially rectangular frame 28 includes an inner side panel 29 connected to the other longitudinal frame member by bolts 27, an outer side panel 30 in spaced parallel relation to the inner panel, and spaced parallel front and rear panels 31 and 32 rigidly interconnecting the side panels, as best seen in FIGS. 2 `and 4. Horizontal gusset plates 34 interconnect the adjacent longitudinal frame member and the rear panel for imparting rigidity to the frame. Itis to be noted that the rectangular `frame 2S is preferably more widely spaced from the truck on one side thereof than on the other.

An elongated substantially cylindrical housing 40 is mounted on the vertical plate 26 and the side panels 29 and 30 of the frame 28 in transversely disposed relation to the direction of travel of the` truck 10 and includes a pair of outer sections41 and 42 and an intermediate sec- `tion 43, all in coaxial alignment. The intermediate sectween extended and contracted positions, -extended from the rod and pivotally connected to the pin Plate; and the outer section 42 is connected at its inner end to the outer side panel 30. The housing does not extend through the frame, as best seen in FIG. 3.

An inverted, upwardly arched, U-shaped member `518 provides opposite lower ends rigidly connected, as by welding, to the outer ends of the outer sections 4 1 and 42 of the housing and an intermediate section extended transversely `of the truck It) in vertically spaced relation to the housing. Angle brackets 49 interconnect the intermediate section of the arched member and vthe longitudinal frame members Y25. An elongated shaft 50 is coaxially extended through the housing et) and is rotatably journaled therein for rocking movement by means of bearings 51. It is :to be `noted that the shaft does extend through the side panels 29 and 3d of the frame 28. Elongated braces 52 rigidly interconnect the opposite outer ends ofthe housing 40 and the longitudinal frame members 25 of the .chassis 11.

Elongated load supporting arms 58 provide inner ends 9 Vrigidly connected to the outer ends of therock .shaft 50 and opposite radially outwardly'extended .endsll The arms extend in a common direction from the shaft and in a substantially common plane. Further, they are -ofysuch length that the outer ends 4thereof are spaced outwardly and forwardly of the front end of the truck v when the arms are in their lowermost forwardly extended positions, as seen in FIG. l. Ascoopor bucket 61 rigidly' transversely interconnects the outer ends of the anus.

With particular reference to FIGS. 4 and -5, levers 65 provide inner ends rigidly connected to the shaft -50 in longitudinally spaced relation between the side panels 29 and34) of the frame 28 and outer ends radially outwardly extended from the shaftin a common direction and in a common plane angularly related to the arms :58. Substantially semi-circular arcuate links 66 provide mounted ends 67 connected to a pin 68 rotatably mounted in the side panels 29 andil of the frame 28 in forwardly spaced lparallel relation to the shaft 50. 'I'he links also have .,-oppositely extended ends 69 and forwardly disposed edges .70. An arcuate plate 72 rigidly interconnects the links along the forwardly disposed edges thereof and |abuts against the front panel 31 to limit clockwise movement of the links, as seen in FIG. 4. vElongated linkage bars 73 provide opposite ends individually pivotally connected to the outwardly extended ends of the ylevers and the links by means of pins 74 and 75.

An hydraulic ram 82 provides a cylinder 83 and a piston rod 84 longitudinally reciprocal in the cylinder be- A lug 85 is 75 intermediate the links 66. A hinge 86 pivotallyinterconnects the cylinder and the side panels 29 and.30 for elevational pivotal movement of the ram arounda substantially horizontal axis transversely of the chassis 11.

With reference to FIG. 2, a reservoir 90 is mounted on one of the longitudinal frame members 25 for containing a supply 'of hydraulic fluid. An hydraulic pump 91 is mounted on a strut 92 transverselyinterconnecting the ,fr-ame members and is adapted to be energized by means of a drive shaft 93 associated with the truck `10. nA control .valve 95 is also mounted on the strut and is connected to vthe pump by means of a hose 96. Inlet and `outlet hoses 98 and 99 interconnect opposite ends ofthe cylinder` 83 and the valve. In addition, a supply hose I100'interconnects the pump and the reservoir and a return hose 101 interconnects the valve and the reservoir. The valve has two positions, one of which connects the pump to the cylinder for moving the rod 84 to its expanded position` and connects the opposite end of Vthe cylinder to the lreservoir for returning liuid thereto. In the other position of the valve, the pumpris connected to the cylinder'. for retracting the rod, and Athe opposite end of the cylinder'is con- -nected to feed back 'to the reservoir. A valve control frod 103 is connected to the valve and extendslforwardy in the truck for control in the cab 17 thereof.

Operating The operation of the described embodiment of the subject invention is believed t be readily apparent and is briefly summarized at this point.-

With the truck 10 and armsV 58 in the positions shown in FIG. l, the truck is driven forwardly to shove the scoop 61 into a mound or pile of material to be loaded, not shown. It is to be noted that in their'loading positions, the arms are nearly horizontal so that minimum forward driving force is required to insert the scoop into the mound of material. When the scoop is filled, the control rod Y183 is longitudinally adjusted to move the valve 95 into its ram contracting position. This slides the rod 84inwardly of the cylinder 83, that is, to the left in FIG. 4. The links 66 are Vthereby pivoted in a counterclock- Wise direction in FIG. 4, thereby to apply ia turning force to the levers 65 through the linkage bars 73. This' rotates or rocks the shaft 50 in a counterclockwisev direction to elevate the arms 58 andthe loading scoop 6l. connected thereto.

The arms 58 are raised into their dumping positions by continued retraction of the ram 82 wherein the scoop 61 is vertically spaced above the receptacle 14 in an upsidedown position to permitV material therein to gravitate into the receptacle. The angularity of the arms in their dumping position is shown in FIG. 5. Although the arms move through an angle of approximately r15 5 from their loading to their dumping positions,the pin 75 only moves through an angle of approximately '100V aboutthe pivot pin 68. Further, it will be observed by reference to FIGS. 4 and 5 that the extent of pivotal movement of the hydraulic ram 82 is negligible. The levers Iand the linkage bars only move'slightly below the frame 28 n the extreme dumping positions of the arms.

Of signicance is the fact that the maximum mechanical advantage is obtained when the 'initial 'lifting force is applied to the arms 58 by the hydraulic ram 82. This is best understood by reference to FIGS. 4 and 5. In FIG. 4, it will be noted that force applied to the levers 65 tending to rotate the shaft 50 is substantially at right angles to the levers. However, as the arms approach their vertical positions, the angle between the linkage bars and the levers decreases. Of course, after the arms move just beyond their verticalpositions, gravity assists in moving them to their dumping positions so that the reduction in mechanical advantage is of little consequence and it will be seen that the greatest advantage is attained at the positions of greatest need.

From the foregoing, it will be evident that ar highly advantageous linkage has been provided for interconnecting the load supporting arms 58 and the hydraulic ram 82. The linkagefenables the more efficient application of lifting force to the arms by the ram, increases mechanical advantage, minimizes Vspace requirements, reduces maximum power requirements and permits the attainment of substantial structural economies. Although shown and described in connection with a specific environment, namely that of self-loading vehicles, it will be evident that theinvention has utility in other environments where similar problems are involved.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that .departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent'devices Vand apparatus. i

Having described my invention, what I claim as new and desire to secure by Letters Patent is: Y

1. In a vehicle having a load receptacle, opposite sides,

and forward `and rearward end portions; an elongated end portions, the shaft having ends extended laterally outwardly of the vehicle; elongated arms rigidly secured to the ends of the shaft and radially extended therefrom in a common direction and in substantia-lly the same plane; and a load carrying scoop rigidly extended between and interconnecting the extended `ends of the arms; an apparatus for elevationally adjustably moving the arms between lower loading positions forwardly extended from the forward end portion of the Vehicle and upper rearwardly inclined dumping positions with the scoop in dumping position over the loading receptacle and wherein the arms are in obtuse angular relationship to their loading positions comprising a lever rigidly connected to lthe shaft and radially extended therefrom in angular relationship to the arms; a semi-circular link having a lower end pivotally mounted on the vehicle in forwardly eccentric relation to the shaft and an upper end; a linkage bar pivotally interconnecting the upper end of the link and the extended end of the lever; and an hydraulic ram having a cylinder pivotally connected to the vehicle rearwardly of the shaft for elevational pivotal movement around an axis parallel to the shaft and a piston rod pivotally connected to the upper end of the link coaxially with the pivotal interconnection of the link and the linkage bar, the ram being extensible and retractable for pivoting the arms between their loading and dumping positions.

2. In a vehicle having a load receptacle, opposite sides and forward and rearward end portions; an elongated shaft; bearings mounted on the vehicle and journaling the shaft transversely of the vehicle in a substantially horizontal position intermediate its forward and rearward end portions, the shaft having ends extended laterally outwardly of the vehicle; elongated amas rigidly secured to CTL the ends of the shaft and radially extended therefrom in a common direction and in substantially the same plane; and a load carrying member rigidly extended between and interconnecting the extended ends of the arms; an apparatus for elevationally adjustably moving the arms between lower loading positions forwardly extended from the forward end portion of the vehicle and upper rearwardly inclined dumping positions with the member in dumping position over the loading receptacle and wherein the arms are in obtuse angular relationship to their loading positions comprising a lever rigidly connected to the shaft and radially extended therefrom in angular relationship to the arms; -a substantially semi-circular link having a lower end pivotally mounted on the vehicle in forwardly eccentric relation to the shaft and an upper end; a linkage bar pivotally interconnecting the upper end of the link and the extended end of the lever; and powered means pivotally connected to the upper end of the link coaxially with the pivotal interconnection of the link and the linkage bar, and being extensible `and retractable for pivoting the arms between their loading and dumping positions.

3. The apparatus of claim 1 wherein Ithe lever and the linkage bar are substantially straight and wherein the shaft and the pivotal connection of the lower end of the link are in a substantially common horizontal plane.

References Cited in the le of this patent UNITED STATES PATENTS 303,111 Boecher Aug. 5, 1884 .2,386,216 Hay Oct. 9, 1945 2,498,144 Thomas Feb. 20, 1950 2,807,951 Gerhardt et al. Oct. 1, 1957 2,827,793 Dyer Mar. 25, 1958 

